Device for assembling axisymmetric components

ABSTRACT

The present invention relates to an axisymmetric structural component ( 1 ), one of the ends of which is fitted with an inner circular flange ( 2 ) for assembling, by bolting, the said axisymmetric structural component ( 1 ) with a second axisymmetric structural component ( 10 ), the said flange comprising housings ( 60, 61, 62, . . .  ) for receiving fixing elements ( 70, 71, 72, . . .  ) such as bolts, pins or threaded rods, the said housings ( 60, 61, 62, . . .  ) being arranged on the circumference of the said flange ( 2 ) at regular intervals, characterized in that each housing ( 60, 61, 62, . . .  ) is, in longitudinal section (A-A) along a plane passing through the rotational axis of the component ( 1 ), T-shaped and consists of a first essentially cylindrical portion ( 6 ) which is longitudinally open on the inner face (x) of the axisymmetric structural component ( 1 ) and transversely open on the contact face (y) of the flange ( 2 ) in the assembly, on which portion is mounted a second essentially semi-cylindrical portion ( 6′ ) which is also longitudinally open on the inner face (x) of the said structural component ( 1 ), the second portion ( 6′ ) having an essentially D-shaped transverse section, the diameter of the first cylindrical portion ( 6 ) being less than the diameter of the semi-cylindrical portion ( 6′ ).

SUBJECT OF THE INVENTION

[0001] The present invention relates to a novel type of flange forfirmly securing two axisymmetric components by bolting and which is thusaffixed to one of the two components.

STATE OF THE ART

[0002] Flanges which are produced directly by turning in the thicknessinside or outside at least one of the components are usually used forassembling axisymmetric components by bolting.

[0003] The term “bolting” means firmly securing by screwing tight usingbolts or screws, pins or threaded rods which may be combined with nuts.

[0004] The type of flange most commonly used for assembling axisymmetriccomponents, for example the bolted cones used as bearing pedestals, isan outer flange with or without reinforcements.

[0005] The flange factor is defined as a factor which takes into accountthe fact that the axis of the force passing through the body of thesupport and the axis of the screw are misaligned, which results in thecreation of a bending moment. The value of the flange factortheoretically ranges between 1 (alignment of the forces) and infinity(complete misalignment).

[0006] The flange factor is proportionately larger the greater themisalignment. The reason for this is that this misalignment generates alever arm (bending moment) which introduces an increase in the forcepassing through the screws during a detachment of the flanges. A largeflange factor (>>1) is thus harmful to the mechanical behaviour of abolted assembly.

[0007] The aim of the presence of reinforcements on the flange is toreduce the flange factor. The reason for this is that thesereinforcements make it possible to reduce the abovementioned lever arm.

[0008] Inner flanges are also known as making it possible to reduce theflange factor, but generally they nevertheless do not have anyreinforcements since they are very problematic to produce.

Aims of the Invention

[0009] The present invention aims to propose a device for assembling twoaxisymmetric components by bolting, which does not have the drawbacks ofthe prior art.

[0010] In particular, the present invention aims to propose a solutionwhich has a flange factor of close to 1.

[0011] The present invention is also directed towards proposing aprocess for producing an inner flange arranged on an axisymmetricstructural component, this process being easy to carry out.

Main Characteristic Elements of the Invention

[0012] The present invention relates to an axisymmetric structuralcomponent, one of the ends of which is fitted with an inner circularflange for assembling, by bolting, the said axisymmetric structuralcomponent with a second axisymmetric structural component, the saidflange comprising housings for receiving fixing elements such as bolts,pins or threaded rods, the said housings being arranged on thecircumference of the said flange at regular intervals, characterized inthat the said housings are T-shaped in longitudinal section and consistof a first essentially cylindrical portion which is longitudinally openon the inner face of the axisymmetric structural component andtransversely open on the contact face of the flange in the assembly, onwhich is mounted a second essentially semi-cylindrical portion which isalso longitudinally open on the inner face of the said structuralcomponent, the second portion having an essentially D-shaped transversesection, the diameter of the first cylindrical portion being less thanthe diameter of the semi-cylindrical portion for each of the housings.

[0013] Advantageously, the axisymmetric structural component is made ofaluminium.

[0014] The invention also relates to a process for manufacturing aninner circular flange arranged on an axisymmetric structural component,which is preferably conical or cylindrical, and which has housings forreceiving fixing elements such as bolts, pins or threaded rods,characterized in that the said housings are machined at regularintervals on the circumference of the said flange in particular using amilling cutter which is essentially T-shaped and such that the axis ofthe said milling cutter moves, during machining, in a direction which isessentially perpendicular to the rotational axis of the said component,preferably radially, while at the same time remaining parallel to thisrotational axis.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIGS. 1a and 1 b each represent a perspective view of anaxisymmetric component fitted with an outer flange with reinforcements,according to the prior art.

[0016]FIG. 2 represents a perspective view of an axisymmetric componentfitted with an inner flange with reinforcements, according to the priorart.

[0017]FIG. 3 represents a perspective view of an axisymmetric componentfitted with an inner flange with reinforcements, according to theinvention.

[0018]FIG. 4 represents a view in section along AA of an assembly of twoaxisymmetric components, one of which is fitted with a flange accordingto the invention, as represented in FIG. 3.

DESCRIPTION OF ONE EMBODIMENT OF THE PRIOR ART

[0019]FIGS. 1a and 1 b represent one particular embodiment of anaxisymmetric structural component (for example a cone) to be assembled,according to the prior art.

[0020] The conical component 1 to be assembled is fitted on itscircumference with an outer flange 2 which has circular apertures 5 forbolting onto a second component to be assembled. These apertures arearranged at regular intervals in recesses 3 machined into the thicknessof the cone. The machining is carried out such that material, thereinforcements 4, is left between the recesses 3.

[0021] In order to reduce the flange factor, it is also possible tomachine an inner flange, as represented in FIG. 2. In this case, it istheoretically possible to have reinforcements 4 between the recesses 3;however, in practice, this operation is difficult to perform.

DESCRIPTION OF ONE PREFERRED EMBODIMENT OF THE INVENTION

[0022] The present invention solves this problem by producing a flangeinside the first axisymmetric structural component to be assembled asrepresented in FIGS. 3 and 4.

[0023] In a first stage, a solid flange 2 is produced by turning insidethe first axisymmetric structural component 1 to be assembled, whichcorresponds in this case to a conical component. This flange is thenmachined in particular using a T-shaped milling cutter in order to makethe orifices corresponding to the housings 60, 61, . . . into which maybe introduced the head of a bolt 70, 71, . . . to assemble the conicalcomponent 1 with the second axisymmetric structural component 10 asshown more particularly in FIG. 4.

[0024]FIG. 4 represents a view in section A-A along a plane passingthrough the rotational axis of the component 1, represented in FIG. 3.Such a section will be referred to hereinbelow as a “longitudinalsection”. Similarly, the term “cross section” will be denotedhereinbelow as being the intersection of the component 1 with a planewhich is perpendicular to its rotational axis.

[0025] Each of the housings 60, 61 . . . will thus be T-shaped inlongitudinal section. Each housing will consist of a first essentiallycylindrical portion 6 which is longitudinally open on the inner face (x)of the axisymmetric structural component 1 and transversely open on thecontact face (y) of the flange 2 in the assembly, on which portion ismounted an essentially semi-cylindrical second portion 6′ which is alsolongitudinally open on the inner face (x) of the said structuralcomponent 1.

[0026] To assemble the two axisymmetric components 1 and 10, the flange2 is firmly secured to the axisymmetric component 10 with bolts with aD-shaped head and optionally washers of the same shape.

[0027] This technique for producing an inner flange has severaladvantages:

[0028] the fastening structure is such that the flange factor is veryclose to 1;

[0029] the technique is industrially viable, in particular for smalltaperings of the components to be assembled;

[0030] the use of material is optimized, which may be essential with theuse of aluminium, the specific strength of which is low. The reason forthis is that, for a given overall size, the amount of material availableis limited.

1. An axisymmetrical structural component, comprising: an inner circularflange, a plurality of housings for receiving fixing elements, whereinsaid housings are T-shaped in a longitudinal section along a planepassing through the rotational axis of said component and comprise acylindrical portion, wherein said cylindrical portion is longitudinallyopen on the inner face of said component and transversely open on thecontact face of said flange, on which a semi-cylindrical portion ismounted, said semi-cylindrical portion being longitudinally open on theinner face of said component and having a D-shaped transverse section,the diameter of said cylindrical portion being less than the diameter ofsaid semi-cylindrical portion.
 2. The axisymmetrical structuralcomponent of claim 1 , wherein said component comprises aluminum.
 3. Theaxisymmetrical structural component of claim 1 , wherein said housingsare arranged on the circumference of said flange at regular intervals.4. The axisymmetrical structural component of claim 1 , wherein saidreceiving fixing elements are selected from the group consisting ofbolts, pins and threaded rods.
 5. A process for manufacturing an innercircular flange on an axisymmetrical structural component comprisinghousings for receiving fixing elements, said process comprising:machining said housings on the circumference of said flange at regularintervals using a milling cutter, wherein said cutter is essentiallyT-shaped and during milling the axis of said milling cutter moves in adirection which is perpendicular to the rotational axis of saidcomponent while at the same time remaining parallel to said rotationalaxis.
 6. The process of claim 5 , wherein said axisymmetrical componentis conical or cylindrical.
 7. The process of claim 5 , wherein saidhousings are adapted for receiving fixing elements selected from thegroup consisting of bolts, pins and threaded rods.